Calendar Widget for Android got a new compact and clear "Single line" layout, see the screenshots https://github.com/plusonelabs/calendar-widget/issues/42#issuecomment-289261236
To be honest, I dreamed about something like this since the first day I joined this Open Source project two years ago :-) Looking at what this layout brings to us, I don't understand, why I didn't do this earlier. Probably I thought that addition of an alternative layout would be a too hard task for me... but it took a working day only.
This is only one of several recent improvements of the Calendar Widget, available at Google Play and f-droid. These changes are not released yet, but as a Source code is freely available, you can start playing with them right now https://github.com/plusonelabs/calendar-widget